Butyl rubbers are copolymers of isobutylene with small amounts of a conjugated diene, usually isoprene, which provides double bonds allowing the rubber to be vulcanized with sulphur and other vulcanizing agents. Butyl rubbers possess a variety of inherently satisfactory properties which has enabled them to find utility in many commercial areas. Among their satisfactory inherent properties are their impermeability to air, high damping of low frequency vibrations, and good resistance to aging, heat, acids, bases, ozone and other chemicals after vulcanization, which renders them well suited for use in a variety of applications including articles requiring low or reduced permeability to air. Examples of such articles include, but are not limited to, tire inner tubes, tire curing bladders and various other air bladders. In the tire industry's continuing quest for improved inner tubes and liners, an elastomeric compound which, after vulcanization, exhibits a reduction in air permeability over conventional inner tubes and liners would be desirable.